AZ_UIScrollView实现图片轮播器注意点
UIScrollView实现图片轮播器
- UIScrollView
- 当发现点击其它控件轮播器停止工作时不要忘了察看主线程的工作模式
- 设置UIPageControl的背景图片只能通过KVC来设置
具体代码如下：
// ViewController.m
// AZScrollViewTest
//
// Created by azhang on 16/11/20.
// Copyright © 2016年 azhang. All rights reserved.
//
#import "ViewController.h"
@interface ViewController ()<UIScrollViewDelegate>
@property (weak, nonatomic) IBOutlet UIScrollView *scrollView;
@property (weak, nonatomic) IBOutlet UITextView *textView;
@property (weak, nonatomic) IBOutlet UIPageControl *pageControl;
/*定时器*/
@property(nonatomic,weak)NSTimer *timer;
@end
@implementation ViewController
- (void)viewDidLoad {
[super viewDidLoad];
//UIScrollView
//1.设置尺寸
CGFloat scrollWidth=self.scrollView.frame.size.width;
CGFloat scrollHeight=self.scrollView.frame.size.height;
NSInteger pages=5;
//2.添加轮播图片
for (int i=0; i<pages; i++) {
UIImageView *imageView=[[UIImageView alloc]init];
UIImage *image=[UIImage imageNamed:[NSString stringWithFormat:@"img_0%d",i+1]];
imageView.frame=CGRectMake(scrollWidth*i, 0, scrollWidth, scrollHeight);
imageView.image=image;
[self.scrollView addSubview:imageView];
}
//3.设置滚动样式
//滚动高度设定为零时在垂直方向无法滚动
self.scrollView.contentSize=CGSizeMake(scrollWidth*pages, 0);
//开启分页功能
self.scrollView.pagingEnabled=YES;
//隐藏提示条
self.scrollView.showsHorizontalScrollIndicator=NO;
//4.UIPageControl
self.pageControl.hidesForSinglePage=YES;
self.pageControl.numberOfPages=pages;
[self.pageControl setValue:[UIImage imageNamed:@"current"] forKey:@"_currentPageImage"];
[self.pageControl setValue:[UIImage imageNamed:@"other"] forKey:@"_pageImage"];
//4.添加定时器
[self startTimer];
//5.设置scrollView的代理
self.scrollView.delegate=self;
}
/**
* 开启定时器
*/
-(void)startTimer
{
//开启定时器
self.timer=[NSTimer scheduledTimerWithTimeInterval:2.0 target:self selector:@selector(nextPage:) userInfo:nil repeats:YES];
//NSDefaultRunLoopMode(默认)：同一时间只能执行一个任务
//NSRunLoopCommonModes（公用）：设置主线程在同一时间可以分配一定时间处理多个任务
[[NSRunLoop mainRunLoop]addTimer:self.timer forMode:NSRunLoopCommonModes];
}
//停止定时器
-(void)stopTimer:(NSTimer *)timer
{
[timer invalidate];
}
//下一页
-(void)nextPage:(NSTimer *)timer
{
NSInteger page=self.pageControl.currentPage+1;
if(page==5) {
page=0;
}
[self.scrollView setContentOffset:CGPointMake(self.scrollView.frame.size.width*page, 0) animated:YES];
NSLog(@"%zd",page);
}
#pragma mark-UIScrollView的代理方法
//开始拖拽的同时关闭定时器
-(void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
[self.timer invalidate];
}
//停止拖拽的同时开启定时器
-(void)scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
[self startTimer];
}
//只要滚动就会调用
-(void)scrollViewDidScroll:(UIScrollView *)scrollView
{
int page=(int)(scrollView.contentOffset.x/scrollView.frame.size.width);
self.pageControl.currentPage=page;
}
@end
